Firing a gun is considered in most, if not all states, to be the use of deadly force, regardless of whether you miss or are firing blanks. Having blanks suggests he didn't think that the situation really merited the use of deadly defensive force, and he's going to be second-guessed six ways from Sunday by the police and prosecutors about his judgement and justification for using deadly force.

__________________Not a blacksmith could be found in the whole land of Israel, because the Philistines had said, "Otherwise the Hebrews will make swords or spears!"1 Samuel 13:19